Breakpad processor: Support negative literals in the postfix evaluator.
Breakpad processor: Support negative literals in the postfix evaluator.

Some versions of the libstdc++, the GNU standard C++ library, have
stream extractors for unsigned integer values that permit a leading
'-' sign (6.0.13); others do not (6.0.9). Regardless of the behavior
of the extractors, Breakpad postfix expressions should support
negative literals.

a=jimblandy, r=nealsid


git-svn-id: a14e546401035be51a469fbea25ecce70a1a22f2@537 4c0a9323-5329-0410-9bdc-e9ce6186880e

tomgr/google-breakpad,tomgr/google-breakpad,tomgr/google-breakpad,tomgr/google-breakpad,tomgr/google-breakpad